1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147
|
/*
* Copyright (C) 2001, 2002, and 2003 Roy Keene
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*
* email: dact@rkeene.org
*/
/*
Encrypt data.
*/
#include "dact.h"
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#ifdef HAVE_STDLIB_H
#include <stdlib.h>
#endif
#ifdef HAVE_STRING_H
#include <string.h>
#endif
#ifdef HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif
#ifdef HAVE_SYS_STAT_H
#include <sys/stat.h>
#endif
#include <fcntl.h>
#include <stdio.h>
#include <math.h>
#include "cipher_psub.h"
#include "parse.h"
#include "ui.h"
#if defined(USE_MODULES) && defined(AS_MODULE)
#include "module.h"
uint32_t DC_NUM=3;
uint32_t DC_TYPE=DACT_MOD_TYPE_ENC;
void *DC_ALGO=cipher_psub;
char *DC_NAME="psubst (MOD)";
#endif
int cipher_psub(const unsigned char *inblock, unsigned char *outblock, const int blksize, unsigned char *key, const int mode) {
switch (mode) {
case (DACT_MODE_CINIT+DACT_MODE_CDEC):
case (DACT_MODE_CINIT+DACT_MODE_CENC):
case DACT_MODE_CINIT:
return(cipher_psub_init(mode,key));
break;
case DACT_MODE_CDEC:
return(cipher_psub_decrypt(inblock, outblock, blksize, key));
break;
case DACT_MODE_CENC:
return(cipher_psub_encrypt(inblock, outblock, blksize, key));
break;
}
return(0);
}
int cipher_psub_init(const int mode, unsigned char *key) {
return(cipher_psub_init_getkey(mode-DACT_MODE_CINIT,key));
}
int cipher_psub_init_getkey(const int mode, unsigned char *key) {
char *phrase;
char *keyreg;
phrase=dact_ui_getuserinput("Passphrase: ",128,1);
memcpy(key,keyreg=cipher_psub_generatekey(phrase),257);
free(keyreg);
return(257);
}
char *cipher_psub_generatekey(const char *passphrase) {
char *keybuf, used[256], hbuf[4];
int i,m,x,loc=0,num;
double d;
keybuf=malloc(1024);
for (i=0;i<256;i++) used[i]=0;
if (strlen(passphrase)<3) { num=257; } else { num=((259/((int) (strlen(passphrase)/3)))+1); }
for (m=0;m<strlen(passphrase);m+=3) {
memcpy(hbuf,passphrase+m,3);
hbuf[3]='\0';
d=hash_fourbyte((unsigned char *) hbuf, '\0');
for (i=0;i<num;i++) {
d=(sin(tan(d))*(255*5));
x=((abs((int) d)&0x3ff)-255);
if (x<0 || x>255 || used[x]) { i--; continue; }
used[x]=1;
if (loc==0) used[x]=0;
keybuf[loc++]=x;
if (loc==257) break;
}
if (loc==257) break;
}
return(keybuf);
}
int cipher_psub_encrypt(const unsigned char *inblk, unsigned char *outblk, int blksize, unsigned char *key) {
int i,mod;
static int keyoffset=0;
mod=(int) key[0];
for (i=0;i<blksize;i++) {
if (!(i%mod)) {
keyoffset=((keyoffset+1)&0xff);
}
outblk[i]=key[((((int) inblk[i])+keyoffset)&0xff)+1];
}
return(blksize);
}
int cipher_psub_decrypt(const unsigned char *inblk, unsigned char *outblk, int blksize, unsigned char *key) {
int i,mod,x;
char reversekey[256];
static int keyoffset=0;
mod=(int) key[0];
for (i=1;i<257;i++) reversekey[(int) key[i]]=(i-1);
for (i=0;i<blksize;i++) {
if (!(i%mod)) {
keyoffset=((keyoffset+1)&0xff);
for (x=0;x<256;x++) reversekey[(int) key[((x+keyoffset)&0xff)+1]]=x;
}
outblk[i]=reversekey[(int) inblk[i]];
}
return(blksize);
}
|